The wren is a small, active bird that can be found in many backyards and gardens. With proper housing, wrens can become delightful backyard visitors that provide entertainment with their busy, inquisitive antics. When considering a bird box for wrens, there are some key factors to take into account to make sure the box suits the needs of these tiny songbirds.
What are the requirements for a wren bird box?
Wrens have some specific requirements when it comes to nesting boxes that differ from other common backyard birds like chickadees or bluebirds. Here are the key considerations for a properly constructed wren house:
Small Entrance Hole
Wrens are very small birds, so the entrance hole is a vital detail. The entry should measure between 1 to 1 1⁄4 inches in diameter. This helps prevent larger birds from attempting to move in and disturb the wren’s nest.
Shallow Depth
The interior floor space of a wren house should be shallow, with a depth of 4 to 6 inches from the bottom of the entrance hole to the floor. Wrens build domed nests that fill much of the interior space, so too deep of a box may prevent them from properly constructing their nest.
Good Ventilation
Proper ventilation is important for any bird house, and wren boxes are no exception. Good air flow discourages condensation which can lead to mold or make the interior damp. Vents under the roof overhang help allow hot air to escape.
Predator Guard
Wrens are vulnerable to predators, so an external guard of some sort is recommended. A simple metal guard with 1⁄4 inch openings around the entrance hole prevents sneak attacks but does not obstruct the adult wrens from entering.
No Perch
Surprisingly, a perch or landing pad is not recommended for wren houses. Wrens prefer to fly directly into their box entrance. Perches can also provide a foothold for predators trying to access the nest.
Where should I place a wren house?
Proper placement of a wren domicile on your property can increase the chance of attracting a pair to next. Here are some tips on situating a nesting box:
Away from Feeders
It is better not to mount the wren abode right next to busy bird feeders. Too much action can deter wrens from taking up residence. They prefer a tucked away, secluded spot.
5 to 10 Feet High
Mount the nesting box on a tree trunk or sturdy pole at a height between 5 to 10 feet. This keeps the nest safely away from ground predators.
Eastern Exposure
Choosing an easterly facing direction ensures the entrance does not receive too much intense afternoon sun and heat which could overheat the nest. An eastward orientation provides morning warmth.
Hidden With Vegetation
Situate the box near or within vegetation to provide concealment from predators and shelter from harsh weather. Ideal spots are near a trellis covered in vines or within a dense shrub.
What construction materials should be used?
Wren houses can be made from a variety of common materials with some being more suitable than others. Here are some options:
Cedar Wood
Cedar is a popular choice as it is naturally weather-resistant and provides good insulation. Cedar boxes last for many seasons.
Pine Wood
Pine can be used but is not as durable against moisture and rot as cedar. Pine needs to be treated and finished well.
Plastic
Recycled plastic nest boxes are an option. They hold up well to moisture and will not rot. However, plastic does not provide as much insulation as wood.
Wicker or Straw
All natural woven boxes are attractive but degrade quickly. They provide poor weather protection and limited durability.
Clay or Concrete
Natural clay or cement boxes retain and conduct heat well for the nestlings but are vulnerable to cracking and damage.
What design or style options are available?
There are many creative designs and styles of wren houses to match your own tastes and complement different landscape environments:
Simple Cedar Box
A basic square cedar box with a sloped roof is simple and effective. Add decorative elements like carvings or exterior stains to customize.
House-shaped
Miniature house-shaped boxes with gable or saltbox roofs add a cute architectural element to gardens.
Natural Tree Stump
Hollow out a small log or tree section and add an entrance hole to create a novel rustic wren abode.
Pottery or Gourd House
For a handcrafted alternative, make a nesting space inside a small pottery container or dried gourd.
Bamboo Chutes
Cut sections of bamboo stalks to fashion cylindrical nesting boxes. Seal the ends and add vents.
Tin Can Recycled House
Clean tin cans can be repurposed into quirky wren homes. Use safer resealed bean cans to avoid sharp edges.
Wicker Basket House
Weave or buy a long narrow basket and add an entrance hole for a decorative option. Line it with soft grass or moss.
Conclusion
Providing the perfect nest box tailored to a wren’s preferences and requirements is the first step in attracting a pair to breed in your garden. Wrens can be tempted by man-made abodes that mimic their natural nesting spots in tree holes, stumps, and brush piles. With a properly constructed and located wren house made from durable weather-resistant materials, you may be rewarded with the spectacle of wrens rearing their young in your backyard. Observing the busy activity centered around one of these nesting boxes as adult wrens continuously gather insects to feed their growing brood is a delight for many gardeners. Let creativity guide the design, but be sure to stick to the essential practical elements like small entry holes, good ventilation, and concealment from predators. By understanding a wren’s needs and habitat inclinations, you can provide a welcoming sanctuary for these tiny energetic songbirds.
References
Books:
- Smith, J. (2015). Building Nesting Boxes for Backyard Birds. Lark Press.
- Robinson, M. (2009). Attracting Songbirds: Birdhouses and Feeders. Creative Homeowner Press.
Websites:
- National Audubon Society. “Wren Nest Box Plans.” https://www.audubon.org/news/how-build-wren-house
- The Spruce. “How to Attract Wrens With the Right Birdhouse.” https://www.thespruce.com/wren-bird-houses-386587
Journal Articles:
- Reese, K.P. and K.E. Franzreb. (2005). “Mounting Height and Orientation of Northern House Wren Nest Boxes in Relation to Nest Entrance and Interior Thermal Environment.” Journal of Field Ornithology, 76(2): 112-118.
- Cockle, K.L. and L. Bodrati. (2018). “Chestnut-backed Chickadee (Poecile rufescens) Nest Site Selection and Reproductive Success in Nest Boxes.” Northwestern Naturalist, 99(3): 212-222.